>>> cbs news political director john dickerson is with us now. good morning. >> good morning, charlie. >> what states are most important for the president? you heard norah talking about wisconsin, romney's campaigning in pennsylvania. where is it most important? >> the president is going to all the eight battleground states but ohio. if you look at the numbers, as we're about to here in a minute, if governor romney doesn't win ohio it becomes very hard for him. ohio, wisconsin, iowa, the big fi firewall for the president. >> and for romney, what does he have to do? >> he has to win ohio. we'll go through it here. but ohio is just a key state for him. if he doesn't, then he's got to pick up a lot of other states on the map. let's take a look now, actually, at the route for governor romney. if he gets ohio -- we'll give him ohio here. we'll also give him florida and north carolina, two states where he's doing well. we'll also give him virginia, with its 13 electoral votes. we're starting here with a map of other states that he would definitely get.